Imatinib Zentiva (Imatinib Mesilate)

Imatinib Zentiva targets abnormal tyrosine‑kinase signalling in several hematologic and solid‑tumour indications.

• Chronic myeloid leukemia (CML): reduces leukemic cell proliferation and achieves cytogenetic remission.
• Philadelphia chromosome‑positive acute lymphoblastic leukemia (Ph+ ALL): contributes to disease control and remission.
• Gastrointestinal stromal tumours (GIST): inhibits tumour growth by blocking KIT signalling.
• Other KIT‑positive solid tumours: provides disease stabilisation in selected cases.

• Imatinib Mesilate binds competitively to the ATP‑binding pocket of BCR‑ABL, c‑KIT and PDGFR tyrosine kinases, preventing phosphorylation of downstream substrates. This inhibition blocks proliferative and survival signalling pathways, leading to reduced malignant cell growth and induction of apoptosis in affected tissues.

Adverse reactions may vary in frequency and severity.

Common Side Effects

• Nausea
• Edema (peripheral swelling)
• Muscle cramps or pain
• Fatigue
• Diarrhoea
• Rash or pruritus

Serious or Rare Side Effects

• Hepatotoxicity (elevated liver enzymes, hepatitis)
• Severe neutropenia or thrombocytopenia
• Cardiac failure or reduced left‑ventricular ejection fraction
• Pulmonary arterial hypertension
• Tumour lysis syndrome
• Stevens‑Johnson syndrome or toxic epidermal necrolysis

Before initiating therapy, clinicians should assess baseline organ function and monitor patients regularly.

• Blood count monitoring: perform complete blood counts at baseline and periodically.
• Liver function assessment: check hepatic enzymes before treatment and during therapy.
• Cardiac evaluation: review cardiac history and monitor for signs of heart failure.
• Pregnancy safety: avoid use in pregnancy (Category D) and advise effective contraception.
• Elderly caution: start at lower doses if frailty or comorbidities are present.
• Store at room temperature: keep in the original container, protect from moisture and light.

Imatinib may interact with several co‑administered medicines, altering efficacy or safety.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): increase plasma levels.
• CYP3A4 inducers (e.g., rifampicin, carbamazepine): reduce exposure.
• Antacids containing aluminium or magnesium: impair absorption.
• Warfarin: may potentiate anticoagulant effect and raise INR.
• QT‑prolonging agents (e.g., sotalol): increase risk of arrhythmia.

Moderate Interactions (Monitor Closely)

• CYP3A4 substrates (e.g., midazolam, cyclosporine): may require dose adjustment.
• Diuretics (e.g., furosemide): monitor electrolytes and renal function.
• Live vaccines: consider timing due to immunosuppression.
• NSAIDs: watch for additive gastrointestinal toxicity.
• Oral contraceptives: efficacy may be reduced, advise alternative contraception.